/Engine/Source/Runtime/RenderCore/Public/ShaderPipelineCache.h
Delegate signature for being notified when currently viable PSOs have started to be precompiled from the cache, and how many will be precompiled
typedef TMulticastDelegate_TwoParams< void, uint32, const [FShaderCachePrecompileContext](API\Runtime\RenderCore\FShaderPipelineCache\FShaderCachePrecompileContext) & > FShaderPrecompilationBeginDelegate